#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
int main()
{
    printf("I am running...\n");
    pid_t id = fork();
    if(id == 0){ //child
        int count = 5;
        while(count){
            printf("I am child...PID:%d, PPID:%d, count:%d\n", getpid(), getppid(), count);
            sleep(1);
            count--;
        }
        printf("child quit...\n");
        exit(1);
    }
    else if(id > 0){ //father
        while(1){
            printf("I am father...PID:%d, PPID:%d\n", getpid(), getppid());
            sleep(1);
        }
    }
    else{ //fork error
    }
    return 0;
}
